There is no immediate end in sight to American dominance of the business-school world. Fourteen of the top 20 schools in our latest ranking of full-time MBA programmes are based there, including the table-topping University of Chicago’s Booth School of Business. It is the fifth time in six years that Chicago has topped our ranking, which is based on a mix of hard data and subjective marks given by the students. One reason for the school’s success is glowing student accounts of its...